JP5256791B2 - Imprint printing apparatus and imprint printing method - Google Patents

Description

  The present invention relates to imposition printing in which images constituting each of a plurality of pages arranged adjacent to each other at the time of completion are printed in a state where they are arranged apart from each other in one sheet.

  2. Description of the Related Art Conventionally, there is known an imprint printing apparatus that performs printing in a state where images constituting each of a plurality of pages arranged adjacent to each other at the time of completion are arranged apart from each other in one sheet. Used for comp output. As such an imprint printing apparatus, for example, a technique described in Patent Document 1 below is known. In this imposition printing apparatus, the contents of image processing are changed according to images and characters, and an overall desired image is formed.

Japanese Patent Laid-Open No. 06-194818 JP 09-261493 A Japanese Patent Laid-Open No. 06-135051

  Further, as disclosed in Patent Document 2 that corrects printing plate data, there is known a technique that adjusts a tone curve for each image and adjusts shading or color misregistration for each image. Furthermore, in a normal printer, a technique called shading correction is also known in order to correct color unevenness in the paper width direction (Patent Document 3).

  However, even when imposition printing is performed after performing these corrections, color unevenness may not be removed. One example will be described with reference to FIG. FIG. 13 shows a case in which image data for four pages (first, second, third, and fourth pages) is imprinted on one sheet of paper. At this time, the second page and the third page may constitute a so-called spread. If there are images a1 and b1 across the left and right pages of the spread, both images form one continuous image, so even if there is slight color unevenness, the viewer will notice the presence of color unevenness. . Of course, if the shading correction for correcting the color unevenness in the paper width direction is performed perfectly, it is considered that such color unevenness does not occur. However, actually, as shown in FIG. Since the three pages are shifted with respect to the paper in both the width direction X and the conveyance direction Y, it is difficult to completely align the printing conditions, and color unevenness occurs. Such a problem is strongly conscious in the case of color printing, but it goes without saying that the same problem occurs even in the case of monotone printing.

SUMMARY An advantage of some aspects of the invention is to solve at least a part of the problems described above, and the invention can be implemented as the following aspects or application examples. That is, the printing apparatus according to the present invention performs printing in a state where images constituting each of a plurality of pages arranged adjacent to each other when completed as a printed matter are arranged apart from each other in one sheet. A printing device with
Printing means for printing at least a multi-tone image on the sheet;
At the time of printing on the sheet, at least the two images of two images that constitute each of a plurality of pages arranged adjacent to each other at the time of completion as the printed matter and are not adjacent on the sheet Correcting means for correcting the density at the time of printing at a location adjacent when the printed material is completed with respect to at least one color used for the printing;
The main point is that

[Application Example 1]
An imposition printing apparatus that performs printing in a state where images constituting each of a plurality of pages arranged adjacent to each other at the time of completion are arranged apart from each other in one sheet,
Printing means for printing at least a multi-tone image on the sheet;
When printing on the sheet, with respect to at least one color used for the printing, the density at the time of printing in the adjacent direction of the image constituting each of the plurality of pages arranged adjacent to each other is determined. An imprinting printing apparatus comprising: a correcting unit for correcting.

An application example of the imposition printing method corresponding to this imposition printing apparatus is as follows:
An imposition printing method for printing an image constituting each of a plurality of pages arranged adjacent to each other when completed in a state where the images are arranged apart from each other in one sheet,
When printing at least a multi-tone image on the sheet, the density at the time of printing in the adjacent direction of the image constituting each of the plurality of adjacently arranged pages is set in the printing. The gist is to correct at least one color used.

  According to this application example, it is possible to correct the density at the time of printing only in an area that needs to be corrected for at least one color used for printing, for each area that forms an image constituting each of a plurality of pages in the sheet. It is possible to reduce unevenness of the color in imposition printing. Further, in such imposition printing, the density at the time of printing can be corrected for a plurality of pages arranged adjacent to each other at the time of completion, for example, the second page area and the third page area shown in FIG. Even a page can be printed with less unevenness.

[Application Example 2]
The above-mentioned imposition printing apparatus,
The range in which the density can be corrected at the time of printing is a predetermined width of an end portion in a direction in which the images are adjacent to each other in an area where the images constituting each of the plurality of pages are arranged.
Such an imprint printing apparatus has an advantage that the process is simplified because the density correction range is limited. The viewer often sees the color of the edge of the image to be attached, even if he sees the unevenness of the image across spread pages, and there is no unevenness by correcting this edge. It is easy to be judged.

[Application Example 3]
The above-mentioned imposition printing apparatus,
The printing unit is capable of printing an image constituting each of a plurality of pages arranged adjacent to each other at the completion in a state of being separated in the vertical and horizontal directions of the sheet,
The imprinting apparatus can set whether or not to correct the density at the time of printing for each image constituting each of the pages.

  In such an imprint printing apparatus, it is possible to correct the density between images printed in a state where the sheets are separated in the vertical and horizontal directions. It is also easy not to perform correction on an image other than the target image.

[Application Example 4]
The above-mentioned imposition printing apparatus,
An imposition printing apparatus comprising: means for storing a table for managing whether or not to correct the density for each image constituting each of the pages.
Such an imprint printing apparatus has an advantage that it becomes very easy to manage whether or not correction is performed for each page.

[Application Example 5]
The above-mentioned imposition printing apparatus,
The printing unit performs printing on the sheet in order from either one of the vertical and horizontal sides,
The correction unit has a correction table that stores the correction value of the density in a direction perpendicular to a direction in which printing is sequentially performed from the one side, and refers to the correction table as the printing progresses. Imprint printing device that performs correction.

  In such an imprint printing apparatus, correction values can be managed with a small table. Such a method is particularly useful in a printing apparatus of a type in which a limited number of rasters are formed at a time, such as a so-called line printer or serial printer.

[Application Example 6]
Such an imprint printing device,
The printing means is means for performing color printing using a plurality of color inks,
The imprinting apparatus according to claim 1, wherein the correcting unit corrects the density at the time of printing for at least one of the plurality of colors of ink.

  In such an imprint printing apparatus, color printing can be performed, and furthermore, correction can be performed for at least one of the inks, and therefore unevenness of the color can be reduced. If correction is performed for all primary colors, color unevenness in a color image can be reduced.

[Application Example 7]
Such an imprint printing device,
The correction means has a plurality of correction data for correcting the density according to the gradation value of the original image, and refers to the correction data according to the gradation value of the image to be printed to correct the density. Imprint printing device.
Such an imprint printing apparatus has a plurality of correction data corresponding to the gradation values, so that unevenness can be reduced finely. Of course, the correction may be performed only when the gradation value is equal to or less than a predetermined value. This is because human eyes are less likely to notice small differences in images with a certain darkness or higher.

[Application Example 8]
Such an imprint printing device,
The printing unit is any one of an inkjet serial printer engine, an inkjet line printer engine, or a page printer engine that sequentially forms a latent image on a photosensitive drum and transfers toner. apparatus.
In such an imprint printing apparatus, correction can be applied to various printer engines to reduce unevenness. Depending on the difference in printing method, the location of unevenness and the cause of the occurrence are different, but it is possible to cope with such differences.

Summary of Examples:
The best mode for carrying out the present invention will be described below with reference to examples. FIG. 1 is an explanatory diagram illustrating a schematic configuration of an imposition printing apparatus 20 as an embodiment. As shown in the figure, the imprint printing apparatus 20 includes a control unit 30 that controls printing, an operation panel 40 that is connected to the control unit 30 to perform various input operations and displays, and a memory card that reads data from a memory card SD. A USB connector 60 for connecting a reader 50, a personal computer PC, etc., an ink cartridge 70 for storing six color inks, a line head 80 capable of ejecting ink across the width direction of the paper PP, and the paper PP are conveyed. A transport mechanism 90 is provided.

  The control unit 30 includes a CPU 31 that controls all processes, a memory 32 that stores programs executed by the CPU 31 and data being processed, a line head driver circuit (hereinafter simply referred to as a driver circuit) for outputting data to the line head 80. 34, a USB interface 36 connected to the USB connector 60 for inputting / outputting data, a memory card interface 37 for exchanging with the memory card reader 50, and an I / O interface 38 for exchanging with the operation panel 40. These elements and circuits are connected to each other by a bus.

  The operation panel 40 includes a plurality of operation keys such as a cursor key and a determination key, and a liquid crystal display panel. In this embodiment, a personal computer PC is connected to the imposition printing apparatus 20, but imposition printing is performed by the imposition printing apparatus 20 alone. Specifically, the user reads a plurality of pages of data stored in the memory card SD or the like into the imprint printing apparatus 20 using the memory card reader 50 and operates the operation panel 40 to operate a surface described later. We perform attached printing. Of course, it is also possible to receive and print data from the personal computer PC. This example will be described as a second embodiment.

  When printing alone, the control unit 30 develops an image to be printed read from the memory card SD in the internal memory 32, performs halftone processing, and converts it into dot on / off data. And print. On the other hand, when printing is performed in response to an instruction from the personal computer PC, so-called halftone processed data, that is, dot on / off data is received from the personal computer PC and printing is performed. The imprinting apparatus 20 performs printing using a line printer engine including an ink cartridge 70, a line head 80, and a paper transport mechanism 90. Note that a color correction circuit CCC, which will be described later, is incorporated in the control unit 30 in the form of a digital signal processor (DSP), the processing content of which will be described later.

  The line printer engine performs printing in units of lines by ejecting multi-color ink dots to desired positions on the paper PP from a line head 80 provided across the width direction of the paper PP. In the present embodiment, the line head 80 has a large number of ink ejection nozzles prepared at a pitch of 1600 dpi for each color for six colors, that is, for six rows, across the width direction of the paper PP. The ink ejection nozzles are configured to receive six colors of ink from the ink cartridge 70 via the ink supply pipe 72. The breakdown of the six color inks is K (black), Y (yellow), LC (light cyan), C (cyan), LM (light magenta), and M (magenta). The line head 80 according to the present embodiment employs a so-called bubble jet method in which each nozzle is provided with a small heater and ink is ejected using bubbles generated when the heater is heated. In this embodiment, the size of the ink droplets to be ejected cannot be changed, but it is possible to adopt a configuration that controls the size of the ink droplets by adopting a method of ejecting ink using piezo distortion or the like. . Further, the in-injection nozzles may be arranged in a straight line at a density of 1600 dpi, or may be arranged in two rows by shifting to the staggered position.

  The line head 80 is provided with a line buffer for each ink output nozzle row, and the control unit 30 transmits data to the line buffer. When data for one column is prepared, the control unit 30 outputs a line head driving pulse in synchronization with the conveyance of the sheet. When receiving the line head driving pulse, the line head 80 ejects ink droplets from the ink ejecting nozzles according to the data prepared in the line buffer. When the ink droplets are ejected, the control unit 30 drives the paper transport mechanism 90 to transport the paper.

  The paper transport mechanism 90 includes a platen 91 provided at a position facing the line head 80, and a paper feed motor 92 that drives the platen 91 and a transport roller (not shown) in synchronization. The paper feed motor 92 is a step motor and rotates in synchronization with a pulse output via the I / O interface 38. When the paper feed motor 92 rotates, the platen 91 and the transport roller rotate, and the paper PP is transported by a predetermined amount, for example, 1/720 inch.

  Since the ink ejection nozzles are slightly shifted in the transport direction of the paper PP, the control unit 30 absorbs these differences and turns the dots on and off so that the ink droplets can be ejected to a desired position. The data preparation, the output of the line head drive pulse, the drive of the paper transport mechanism 90, etc. are all calculated and controlled.

  In this embodiment, the data transmitted to the line head 80 is created by expanding the data read from the memory card SD by the control unit 30. Specifically, the control unit 30 reads the data in the memory card SD using the card reader 50, analyzes the image data, and converts the image data into image data having a predetermined gradation value for each pixel. A process of color-converting the rasterized image data for each pixel and a process of converting the color-converted data into dot on / off data formed by the line head 80 are performed.

Correction data creation process:
Next, creation of correction data in imposition printing will be described. The imprint printing apparatus 20 is designed so that each color ink can be ejected uniformly over the width direction of the paper PP. However, in the actually manufactured line head 80, due to various factors, the paper width direction Some unevenness occurs over the entire area. Various factors such as an error in processing the ink ejection nozzle of the line head 80 and a difference in the supply pressure of ink from the ink cartridge 70 in the width direction of the line head 80 may be considered as causes of such unevenness. It is done. After the adjustment as the imprint printing apparatus 20 is completed as much as possible, the remaining unevenness is first measured by the following method in this embodiment.

  FIG. 2 is a process diagram showing an outline of the correction data creation process. In order to correct the unevenness remaining in the imprint printing apparatus 20, a calibration pattern is first printed (step S10). An example of a calibration pattern is shown in FIG. In short, uniform density data is created across the paper width direction and printed using the line head 80. In FIG. 3, for easy understanding, the pattern is hatched and drawn with a width shorter than the width of the paper PP. However, in actuality, imprinting is performed on a halftone processed solid pattern of a predetermined gradation. Print over a range. Printing is performed for each color. The pattern shown in FIG. 3 shows a pattern obtained by performing halftone processing on a solid pattern having gradation values 32, 64, 96, 128, and 160 in order from the top. The range of gradation values is 0 to 255, but the pattern in the range of gradation values 161 to 255 is not printed. This is because unevenness of a pattern having a high density is difficult to notice. Of course, a uniform pattern may be printed over a range of gradations from 0 to 255. Note that the pattern illustrated in FIG. 3 is printed for six colors of ink.

  Next, the printed pattern is measured in the paper width direction (step S20). Colorimetry may be performed using a colorimeter (not shown). The colorimeter used for such colorimetry is a dedicated machine with its own reading accuracy adjusted precisely. By measuring the color of the paper on which the pattern is printed in the width direction, unevenness in the paper width direction at the time of printing each color which the imprint printing apparatus 20 has is accurately measured. Note that if the imprint printing apparatus 20 is configured as a multifunction machine including a scanner, a simple color measurement process may be performed by reading a pattern using its own scanner. Such a scanner usually has its own error. However, if the error of the scanner is measured in advance and calibration data is prepared, color measurement can be performed even if the scanner of the multifunction machine is used. It is possible.

  After performing color measurement in this way, correction data for each color is created using the measured data (step S30). The creation of the correction data will be described with reference to FIG. The upper part of FIG. 4 shows the measurement result of the pattern of the predetermined color measured in step S20. The example of FIG. 4 is a result of reading a pattern of cyan C with a gradation value of 64 (tone value range is 0 to 255). Among these, the ranges described as “Area A” and “Area B” in FIG. 4 indicate the ranges in which images are placed in imposition printing. Therefore, in step S30, correction data is created for the areas A and B. This is the data shown in the lower part of FIG. The correction data is created so as to cancel the unevenness of the colorimetric density data. That is, in the imprint printing apparatus 20 made completely uniform, the measurement data shown in the upper part of FIG. 4 should exhibit a completely flat characteristic. However, as shown in FIG. 4, the actual imprint printing apparatus 20 has slight unevenness in ink density when viewed in the paper width direction. Correction data is created so as to cancel out such unevenness. In this embodiment, the correction data is created based on the pattern of gradation value 64, but it may be created using a pattern of other gradation values.

  By executing the correction data creation process shown in FIG. 2, correction data is created for each color ink. In this embodiment, the correction data is written in the memory 32 of the control unit 30. The correction data is written into the memory 32 from the personal computer PC. The correction data created using the color measurement result is once taken into the personal computer PC and transmitted to the imprint printing apparatus 20 through the USB connection. The control unit 30 that receives the correction data outputs the correction data. Store in memory 32.

First embodiment:
FIG. 5 is an explanatory diagram showing an outline of processing performed by the imprint printing apparatus 20. The correction data CD created by the colorimetry is prepared in the memory 32. The imprinted image data GD to be printed is read from the memory card SD via the memory card reader 50 and prepared by the halftone process by the control unit 30. Furthermore, correction area designation data AD is prepared for printing. This is data for designating ON / OFF of correction for the areas A and B corresponding to each impositioned page. In this embodiment, the correction area designation data AD is designated by the user using the operation panel 40.

In the imprint printing illustrated in FIG. 5, among the 1 to 4 pages included in the image data, the second page and the third page are arranged at a so-called spread position on the completed document. That is, the second page and the third page are arranged adjacent to each other when the printed matter is completed. Therefore, the correction area designation data AD is designated as follows for each page number 1.
[1] The area designation is “A” and the correction is OFF (ie, no correction is performed).
[2] The area designation is “B” and the correction is on (ON), that is, correction is performed.
[3] The area designation is “A”, and the correction is on (ON), that is, correction is performed.
[4] The area designation is “B” and the correction is OFF (ie, no correction is performed).

  When the operation panel 40 is operated and printing is instructed after the above preparation, the control unit 30 performs the color correction by the built-in color correction circuit CCC and sequentially prints the corrected image data (printer) engine. Send to PE. The color correction circuit CCC is realized as a dedicated digital signal processor (DSP) built in the control unit 30. The color correction circuit CCC sequentially reads the halftone processed image data GD along the paper width direction, and refers to the correction area designation data AD based on the position in the paper width direction. If the area designation is A and the correction is on, the correction data of the area A is read from the correction data CD, and the image data GC is corrected using this correction data. The same applies when the area designation is B and the correction is on. On the other hand, when the correction is turned off by the correction area designation data AD, the correction data CD is not read and the image data GD is output as it is to the printer engine PE. The imposition printing apparatus 20 repeats the reading along the paper width direction and the correction processing using the color correction circuit CCC until the printing of the image data GD is completed.

  As a result, even if the characteristic (A) of the printer engine PE is not completely flat in the paper width direction, this unevenness can be corrected by the correction data CD, and the corrected characteristic (B) is almost flat. It becomes a characteristic. Accordingly, the color unevenness of the second and third pages adjacent to the completion of the printed matter is almost eliminated, and even if the page is configured as a spread page, the color shift becomes difficult to be visually recognized.

  In the above embodiment, the correction data CD has been described in the form of a predetermined graph, but actually, as shown in FIG. 6, it may be prepared as a table associated with coordinates in the paper width direction. Further, as shown in FIG. 7, the correction area designation data AD includes a coordinate As indicating the correction start position for the area A, a coordinate Ae indicating the correction end position, and a coordinate Bs indicating the correction start position for the area B. And coordinates Be indicating the correction end position may be prepared. In this way, the capacity of the correction area designation data AD can be reduced.

Second embodiment:
Next, a second embodiment of the present invention will be described. In the second embodiment, the above-described halftone processing and correction for unevenness in the paper width direction are performed on the personal computer PC side. That is, in the second embodiment, the data used for printing by the imposition printing apparatus 20 is created on the personal computer PC. In this case, the printing apparatus 20 may be a normal printer that does not have the color correction circuit CCC or the like. For imposition printing, a dedicated application program is used. This application program imposes an image representing a plurality of pages created by a DTP (desktop publishing) application program at a predetermined position on the paper PP, performs various processes, and then outputs the image to the printing apparatus 20. . At this time, in the personal computer PC, a printer driver that operates under the OS is activated, and the imposition data received from the application program is expanded to dot on / off data that can be printed by the printing apparatus 20.

  FIG. 8 is a flowchart showing an image correction processing routine executed by the printer driver of the personal computer PC. Prior to this processing, the creation of the correction data (FIG. 2), the creation of the correction area designation data AD, and the input to the personal computer PC described in the first embodiment are completed. In the personal computer PC, all of this information and image data to be printed are once stored in a built-in hard disk (not shown).

  When the process shown in FIG. 8 is started, the printer driver first accesses the image data, and performs a process of reading the image data GD of the coordinate X (step S100). The coordinate X is defined with 0 at the top left end of the image data, and an initial value of 0 is given at the start of processing. As will be described later, the coordinate X is sequentially incremented along with the process and used to read the image data GD along the paper width direction.

  When the image data GD is read, it is next determined whether or not the coordinate X is larger than the value As indicating the start position of the area A to be corrected and smaller than the value Ae indicating the end position of the area A to be corrected ( Step S110). If the coordinate X is within this range, then, a process of reading the correction value CD1 corresponding to the coordinate X in the region A from the correction data CD prepared in advance (step S120). Then, using the correction value CD1, a process for correcting the image data GD is performed (step S130). Here, the correction is performed by multiplying the image data GD by the correction value CD1.

  After correcting the area A in this way, the coordinate X is incremented by 1 (step S140), and it is determined whether or not the processing for one line is completed (step S150). If the process for one line is not completed, the process returns to the above-described step S100 to continue the process. If the coordinate X on the image data GD deviates from the region A (step S110: “NO”), the end position of the region B in which the coordinate X is corrected to be larger than the value Bs indicating the start position of the region B to be corrected next. It is determined whether or not the value Be is smaller than (Step S160). Even if the coordinate X deviates from the area A, the determination in step S160 is “NO” until the next correction area is reached, so the process proceeds to step S140 described above, the coordinate X is incremented, and one line ends. The process is repeated from this determination (step S150).

  On the other hand, if the determination in step S160 is “YES”, that is, if the coordinate X is within this range Bs to Be, then the correction corresponding to the coordinate X in the region B is made from the correction data CD prepared in advance. A process of reading the value CD2 is performed (step S170). Then, processing for correcting the image data GD is performed using the correction value CD2 (step S180). Here, the correction is performed by multiplying the image data GD by the correction value CD2. After correcting the area A in this way, the coordinate X is incremented by 1 (step S190), and it is determined whether or not the processing for one line is completed (step S150). If the process for one line is not completed, the process returns to the above-described step S100 to continue the process.

  When the processing for one line is finished, this routine is once ended, and the processing is moved to the next line. At this time, the coordinate X is initialized to the value 0. The image data GD processed so far is finally converted into dot data indicating dot on / off by the printer driver, and is output to the printing apparatus 20 via the USB connection. The printing apparatus 20 receives the dot data, drives the line head 80 using this data, and prints on the paper PP.

Variations:
As mentioned above, although several Example of this invention was described, this invention is not limited to these Examples, In the range which does not deviate from the summary of this invention, it can implement in a various aspect. . For example, in these embodiments, the correction on / off is determined in units of the area A and the area B on which the image is impositioned. However, the correction may be performed only at the ends of the areas A and B. FIG. 9 is an explanatory diagram showing the state of such correction. The upper part of FIG. 9 shows the correction data CD in the areas A and B used in the above embodiment.

  On the other hand, in the lower part of FIG. 9, a predetermined range including the centers of areas A and B is masked by masks MA and MB, and correction is not performed. Further, as a result of adding the masks MA and MB in this way, in the region B, it is found that the correction data CD in the regions BES and BEE at both ends not masked by the mask MB is almost 1, that is, no correction is necessary. Therefore, the correction is performed only at both ends of the area A, that is, the area AES and the area AEE. As described above, if correction is performed only on the end portions of the impositioned areas A and B, but not on the ends thereof, the correction processing can be simplified, the processing speed can be increased, and hardware such as a memory can be used. Wear resources can be saved.

  In a page (second and third pages in the above-described embodiment) that is placed in a spread position when the printed material is completed, the difference in color between adjacent images is felt very sensitively. Therefore, as in the example shown in FIG. 9, when correction is performed only at both ends of the areas A and B, color unevenness and misalignment are not perceived at adjacent portions on the spread pages. In FIG. 9, the correction is performed at both ends, but the correction may be performed only at the end portion adjacent to the spread.

  When correction is performed only at such end portions, as shown in FIG. 10, transition processing may be performed at the joint between the corrected range (AES or AEE) and the masked area. That is, correction data with a gradient from the correction data CDT at the end of the end area AES of the area A to be corrected to the correction data CDA at the end of the mask area MA that is not corrected (displayed as a solid line JL). The correction is performed using. Even if the actual correction data CD changes as indicated by the broken line BL, the correction is almost equivalent in appearance. In this case, the correction data may be calculated with a predetermined gradient, and it is not necessary to read out the correction data (BL) every time, so that the processing speed can be increased. In this example, the correction data CDA in the mask area has been described as a value of 1 (one that does not need to be corrected), but actually there may be cases where correction is also required in the mask area MA. In this case, since correction is not actually performed in the mask area MA, the correction coefficient in the area AES is not gradually decreased from the end correction data CDT to the correction data CDA at the end of the mask area, but at the end. What is necessary is just to comprise so that it may reduce gradually from the correction data CDT to the value 1 without correction | amendment.

  In the above-described embodiment, the correction is performed using the data measured using the pattern of the gradation value 64 among the gradation value patterns. However, the pattern with a plurality of gradation values is used. You may make fine corrections using the colorimetric data. FIG. 11 is a graph showing an example of measurement of density data detected by the gradation values CK1 to CK6 across the paper width direction. In this example, a large shift is observed at the left end of the sheet, particularly when the gradation value is low. Therefore, instead of multiplying the correction data CD uniformly, correction data corresponding to the gradation value of the image data GD is used. In this way, even when the unevenness in the line head varies depending on the gradation value, it can be finely corrected, and the color shift of the reproduced impositioned image can be reduced. When it is found that such a characteristic is obtained, it is possible to take a countermeasure such that correction is performed only when the gradation value of the image data is equal to or less than a predetermined threshold value.

  In the above embodiment, it has not been specified for which color the correction is performed. For example, when the printing apparatus 20 performs monotone printing, it is only necessary to print a pattern with ink of that color, perform color measurement, and create correction data. In the case of color printing, color measurement is performed in the same manner for all colors, correction data is generated, and correction is performed using this data. FIG. 12 is an explanatory diagram showing an example in which correction data is created for three colors C, M, and Y. In this example, the cyan ink C has a characteristic that requires a large correction amount at the right end in the paper width direction, and the magenta ink M has a characteristic that the correction amount gradually increases toward the left in the paper width direction. The yellow sync Y shows a characteristic that needs almost no correction. Accordingly, correction may be performed for each color ink, and in view of the correction amount, correction may not be performed for yellow ink, but only C and M may be corrected.

  In the above-described embodiments and modifications, ordinary paper is used as the print medium. However, the print medium may be a sheet. For example, even a special film or photographic mat paper can be printed in the same manner. In the above-described embodiments and modifications, the line printer engine that ejects ink from the line head provided across the width direction of the paper is used as the printing unit. A serial printer engine that ejects ink while scanning in a direction that intersects with the image may be used, or an electrophotographic page printer engine that sequentially forms latent images on a photosensitive drum and transfers toner may be used.

It is explanatory drawing which shows schematic structure of the imprint printing apparatus 20 of an Example. It is process drawing which shows correction data creation processing. It is explanatory drawing which shows an example of the pattern used for colorimetry. It is explanatory drawing which shows a mode that correction data are produced from the colorimetric data. It is explanatory drawing which shows the outline | summary of the correction process in 1st Example. It is explanatory drawing which shows the other implementation | achievement form of correction data. It is explanatory drawing which shows the other implementation | achievement form of correction area | region designation | designated data AD. It is a flowchart which shows the image correction process routine in 2nd Example. It is explanatory drawing which shows the process in the case of correct | amending only in the edge part of area | regions A and B. FIG. It is explanatory drawing explaining the case where the process which gave the gradient in the edge part is performed. It is a graph which shows the color-measured density data for every gradation value. It is a graph which shows the correction value about each color of CMY. It is explanatory drawing shown about the reason for which color misregistration is easy to be visually recognized in imposition printing.

Explanation of symbols

DESCRIPTION OF SYMBOLS 20 ... Imprint printer 30 ... Control part 31 ... CPU
32 ... Memory 34 ... Line head driver circuit 36 ... USB interface 37 ... Card reader interface 38 ... I / O interface 40 ... Operation panel 50 ... Memory card reader 60 ... USB connector 62 ... USB cable 70 ... Ink cartridge 72 ... Ink supply tube 80 ... Line head 90 ... Paper transport mechanism 91 ... Platen 92 ... Paper feed motor CCC ... Color correction circuit PC ... Personal computer SD ... Memory card

Claims (8)

An imprint printing apparatus that performs printing in a state where images constituting each of a plurality of pages arranged adjacent to each other when completed as a printed matter are arranged apart from each other in one sheet,
Printing means for printing at least a multi-tone image on the sheet;
When performing printing on the sheet, a images constituting each of the plurality of pages to be positioned adjacent the time of completion as the printed matter, said on the sheet with the two images that are not adjacent, at least the 2 A surface imprinting apparatus comprising: a correcting unit that corrects the density at the time of printing at a location where two images are adjacent when the printed material is completed as to at least one color used for the printing. The imprinting printing apparatus according to claim 1,
The range in which the density can be corrected at the time of printing is a predetermined width of an end portion of an area where an image constituting each of the plurality of pages is arranged in a direction in which the image is adjacent to the printed product when it is completed. Imprint printing device. The imprinting printing apparatus according to claim 1,
The printing unit is capable of printing an image constituting each of a plurality of pages arranged adjacent to each other when completed as the printed matter in a state of being separated in the vertical and horizontal directions of the sheet,
The imprinting apparatus can set whether or not to correct the density at the time of printing for each image constituting each of the pages. The imprint printing apparatus according to claim 3, wherein
An imposition printing apparatus comprising: means for storing a table for managing whether or not to correct the density for each image constituting each of the pages. The imprinting printing apparatus according to claim 1,
The printing unit performs printing on the sheet in order from either one of the vertical and horizontal sides,
The correction unit has a correction table that stores the correction value of the density in a direction perpendicular to a direction in which printing is sequentially performed from the one side, and refers to the correction table as the printing progresses. Imprint printing device that performs correction. The imprinting printing apparatus according to claim 1,
The printing means is means for performing color printing using a plurality of color inks,
The imprinting apparatus according to claim 1, wherein the correcting unit corrects the density at the time of printing for at least one of the plurality of colors of ink. The imprinting printing apparatus according to any one of claims 1 to 6,
The correction means has a plurality of correction data for correcting the density according to the gradation value of the original image, and refers to the correction data according to the gradation value of the image to be printed to correct the density. Imprint printing device. An imposition printing method for performing printing in a state where images constituting each of a plurality of pages arranged adjacent to each other when completed as a printed matter are arranged apart from each other in one sheet,
When printing an image of at least a multi-gradation to the seat, a images constituting each of the plurality of pages to be positioned adjacent the time of completion as the printed matter, said on sheet two images that are not adjacent About the imprinting printing method, the density at the time of printing at a location where at least the two images are adjacent when the printed matter is completed is corrected for at least one color used for the printing.

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